What fuel pressure - Qjet

[mrk5]

I just picked up an adjustable fuel pressure regulator so I could drop fuel pressure down to 1 or 2 on the trail.

What should I set it at for street/highway driving? I'm thinking either 4 or 5.

Oh, and I did search but almost all of the "fuel pressure" threads dealt with TBI.

 

[pauly383]

3.5 to 4 psi street , as far as I can find http://www.mako.com.au/buick/html/qjet_tips.htm

But as far as I know a stock pump and no regulator , on my truck , with a Q-jet , has yet to stall at all

 

[Mad-Dog]

5-7 psi is nominal fuel pressure, why on earth would you wanna drop fuel pressure to 1 or 2 psi on the trail....?

I use a carbureted bypass regulator on a 7 psi mechanical pump to supply a constant 5 psi fuel pressure to the nitrous system and return any un-used fuel back to the tank, the carb gets a steady 7 psi fuel pressure.

bypass regulators are nice because ant un-used is returned to the tank and not sitting stagnant in the line heating up.....cool fuel is good fuel.

 

[mrk5]

On angles it helps keep the needle from unseating on inclines due to fuel pressure since the angle will let the needle unseat easier than on level ground. Just one more way to avoid the expense of FI for a while longer.

 

[pauly383]

Scott , I run at 550 rpm in gear , and I don't stall . Your at a higher altitude , but I still expect the Q-jet to be allright with regular pressure numbers . They way the float and bowl are laid out is just much better , and the needle and seat are much more protected from slosh on these

 

[Mad-Dog]

Oh ok, i learn something new everyday here at CK5.......thanx

 

[R72K5]

7 to 9 psi is stock mechanical carb pressure on Gm apps, like all of them really, v-8s, sixes, etc,

 

[mrk5]

Scott , I run at 550 rpm in gear , and I don't stall . Your at a higher altitude , but I still expect the Q-jet to be allright with regular pressure numbers . They way the float and bowl are laid out is just much better , and the needle and seat are much more protected from slosh on these

Come to think of it, the people that I've talked to about running the regulator were using Holleys. Maybe it helps a holley more than it would a qjet.

 

[pauly383]

Maybe you can take it back ( regulator ) and buy another cool little toy for the toy

 

[Thunder]

You shouldn't need a regulator with a Q-jet as long as you are using the stock pump. As said in above post they dont have slosh problems like Holley and Edelbrock. When set up right. A Q-jet is the next best thing to FI for off road. Q-jet AKA Hillbilly FI.